A semiconductor wafer of, for example, silicon or gallium arsenide is produced in a large diameter, cut and separated (diced) into elemental chips and subjected to the subsequent mounting step. In this process, the semiconductor wafer undergoes dicing and expansion steps in the state of being attached to an adhesive sheet and is transferred to the subsequent pickup and mounting steps.
In the expansion step, the adhesive sheet is extended so that chip spacings are expanded. The objective of the expansion step in which chip spacings are expanded is, for example, to facilitate chip recognition in the die bonding and to prevent device breakage attributed to mutual abuttal of neighboring chips in the pickup step.
Currently, the expansion step is carried out by extending the adhesive sheet with the use of an expanding apparatus.
In most expanding apparatuses, the degree of extension and the torque during the extension are fixed to thereby render difficult adjusting dependent upon the type of adhesive sheet and the size of device.
Accordingly, it has occurred that, when the adhesive sheet is soft, the extending stress is not conveyed to the wafer setting portion to thereby prevent the attainment of satisfactory chip spacings. On the other hand, when the adhesive sheet is hard, the torque of the apparatus is unsatisfactory or the adhesive sheet is torn.